Lighting devices, which are capable of identifying and marking traffic areas of airports and emitting signals, have been utilized. For example, runways and landing strips as well as taxiways of airports have been employing lighting devices that can mark, for example, the beginning, the end, and the middle of a runway and, optionally, individual sections of the runway as well. Halogen lamps, frequently used in such lighting devices, have a typical service life of about 1,000 to about 1,500 hours and therefore, in practice, have to be replaced relatively frequently. A further disadvantage of halogen lamps is that they consume a relatively large amount of power during their operation.
Replacing the halogen lamps with lamps based on semiconductors has been described as related to lighting devices capable of identifying and marking traffic areas. EP 0 898 683 B1 and EP 0 898 684 B1, for example, disclose lighting devices that directly emit visible light. In order to reduce the power consumption and the maintenance expenditure, the light sources are implemented as semiconductor elements, in particular as light-emitting diodes. Light-emitting diodes have a substantially lower thermal power loss and simultaneously a longer service life and greater reliability in comparison to halogen lamps. In order to be able to vary the intensity of light emission of the semiconductor elements in a controlled manner, a corresponding control unit is typically provided. Further lighting devices for identifying and marking traffic areas of airports, in which semiconductor elements are used as light sources, are described, for example, in WO 2009/077010 A1, WO 97/44614 A1, or WO 97/44612 A1.
One disadvantage of the lighting devices, of the related art, used for identifying and marking traffic areas of airports is that an additional transformer is required to adapt the control circuit (provided for the operation of the at least one semiconductor element) to the supply network (the AC network). The presence provision of this additional transformer necessitates higher weight of the lighting device and increases the production costs. In addition, a special construction and connection technology required to implement the resulting lighting device, which leads to substantial structural expenditure necessitated by stringent requirements for the vibration and shock resistance.